(1) Field of the Invention
The present invention relates to a load connector, and more particularly to a load connector in which a circuit board is disposed in the collar and the inner and outer circumferences of the circuit board are respectively electroplated with two annular conductive layers. A chip resistor or a film resistor is disposed between the two conductive layers to shorten the internal using space of the load connector and achieve an optimal electric appliance property.
(2) Description of the Prior Art
In television systems such as cable television system (CATV), closed-circuit television system (STV) and common antenna television system (MATV), coaxial cables are used to transmit the signals to wide customers. Referring to FIGS. 1A and 1B, generally, multiple distributors 10 are disposed on the main trunk of these television systems. The distributors 10 via coaxial cables transmit signals to the customers. However, the number of the customers will not be just equal to the number of the output terminals of the distributors. Therefore, a load connector 12 with impedance coupling is used to connect with the not used output terminal 11 to avoid leakage of the signals which will lead to signal interference. In order to eliminate the signal interference, the load connector is mounted on the not used output terminal to avoid impedance discoupling between the coaxial cable for outputting signals and the coaxial cable of the customers.
Such load connector 12 includes a main body 13 formed with an inner thread section 14 and a receptacle 15. The inner thread section 14 is screwed on a not used output terminal 11. A resistor 16 is positioned in the receptacle 15. A lead 17 at rear end of the resistor 16 extends out of the main body 13 and fixedly soldered on the main body 13. A lead 18 at front end of the resistor 16 extends out of the main body 13 to connect with a contact element of the not used output terminal 11 so as to form impedance coupling.
The requirement for receiving frequency has been higher and higher nowadays. The frequency has been increased from 550 MHz to 1000 MHz or higher. Therefore, the commercially available load connector must be applicable to high frequency. However, the resistor 16 mounted in the conventional load connector 12 is the widely used 75 xcexa9 resistor which has considerably large volume. Therefore, the total length of the load connector 12 is increased relatively. In the case of burglarproof load connector or double-head (male-female head) load connector, the total length thereof will be even longer. The longer the total length of the load connector is, the smaller the back loss of the electric appliance achieved at high frequency is. Such back loss can hardly meet the requirement of U.S. electric appliance specification standard (SCTE) that the back loss should be over 30 dB. Therefore, the excessively long load connector will directly affect the video quality and can hardly meet the requirement of high frequency.
Therefore, it is necessary to provide a load connector which can achieve larger back loss of electric appliance and meet the requirement of high frequency.
It is therefore a primary object of the present invention to provide a load connector in which a circuit board is disposed in the collar. The inner and outer circumferences of the circuit board are respectively electroplated with two annular conductive layers. A chip resistor or a film resistor is disposed between the two conductive layers to greatly shorten the internal using space of the load connector and achieve a good impedance coupling. Accordingly, the total length of the load connector is shortened to achieve an optimal electric appliance property when connected with the distributor.
It is a further object of the present invention to provide the above load connector in which an O-ring is disposed on outer side of the wall of the flange end section of the collar, whereby when the load connector is connected with the output terminal of the distributor, the O-ring is compressed between the output terminal and the collar to achieve a moisture-tight seal.
The present invention can be best understood through the following description and accompanying drawings wherein: